Molded interconnect devices (“MID”) often contain a plastic substrate on which conductive elements or pathways are formed. Such MID devices are thus three-dimensional molded parts having an integrated printed conductor or circuit layout, which saves space for use in smaller devices (e.g., cellular phones). It is becoming increasingly popular to form MIDs using a laser direct structuring (“LDS”) process during which a computer-controlled laser beam travels over the plastic substrate to activate its surface at locations where the conductive path is to be situated. Various materials have been proposed for forming the plastic substrate of a laser direct structured-MID device. For example, one such material is a blend of polycarbonate, acrylonitrile butadiene styrene (“ABS”), copper chromium oxide spinel, and a bisphenol A diphenyl phosphate (“BPADP”) flame retardant. One problem with such materials, however, is that the flame retardant tends to adversely impact the mechanical properties (e.g., deformation temperature under load) of the composition, which makes it difficult to use in laser direct structuring processes. Such materials are also unsuitable for lead free soldering processes (surface mount technology) that require high temperature resistance. In addition, due to surface defects on the substrate, it is often difficult to form pathways having a small and consistent spacing and width.
As such, a need exists for an improved polymer composition that can be activated by laser direct structuring.